topic Re: DNS config in Operating System - HP-UX

DNS config

Ryan Ma — Thu, 18 Apr 2002 01:47:17 GMT

I would like to ask how to config the DNS server to query other DNS server if the hostname is not found in its DB.

Thanks.

Re: DNS config

Steven Sim Kok Leong — Thu, 18 Apr 2002 02:23:42 GMT

Hi,

You have to enable recursion to have your DNS server query other DNS servers on your DNS client's behalf, instead of returning references to other DNS servers for your DNS client to query (non-recursive).

You have to set the following under options in the bind configuration file (named.conf):

recursion yes;

Note however that enabling recursion exposes your DNS server to DNS cache poisoning and performance degradation.

Hope this helps. Regards.

Steven Sim Kok Leong

Re: DNS config

Michael Tully — Thu, 18 Apr 2002 02:23:50 GMT

Hi,

Am I right to assume that this server is a
secondary DNS server?
If so you should have the primary DNS server
listed in your /etc/resolv.conf file.
It should ten go an look up the primary DNS
if it does not find it in either it's own
DNS entries or in it's local /etc/hosts file.
This will depend on how also your
/etc/nswwitch.conf file is configured.

Here is how I have mine:

/etc/resolv.conf
domain domain.com.au
nameserver 10.88.101.2

/etc/nsswitch.conf
hosts: dns [NOTFOUND=continue UNAVAIL=return TRYAGAIN=return] files [NOTF
OUND=return UNAVAIL=continue TRYAGAIN=return]

HTH
Michael

Re: DNS config

Michael Tully — Thu, 18 Apr 2002 03:13:50 GMT

Hi,

Another thought I had how I would set this up.

Your DNS (primary is set up on another machine)

Set up your /etc/resolv.conf file like this:

/etc/resolv.conf
domain domain.com.au
nameserver 10.88.101.2

/etc/nsswitch.conf
hosts: files [NOTFOUND=continue UNAVAIL=return TRYAGAIN=return] dns [NOTFO
UND=return UNAVAIL=continue TRYAGAIN=return]

Note how the system is told to try and
resolve locally before attempting query on
the DNS server. You can of course of more
than one DNS server in which to query.

Michael

Re: DNS config

Michael Tully — Thu, 18 Apr 2002 03:23:53 GMT

If you wanted to set up DNS yourself, the link below provides the necessary information on how to do it:

Start with this document:
http://docs.hp.com/hpux/onlinedocs/B2355-90147/B2355-90147.html

If you need more look here:
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xe3337b8d1de3d5118ff40090279cd0f9,00.html

Re: DNS config

sven verhaegen — Thu, 18 Apr 2002 12:05:32 GMT

wel depending on what you want I would think you are looking for the usage of 'forwarders' , it is enough to put in the root server of your domains config file a forwarder statement pointing to another DNS servers IP , then all other request then your own domain will be sent there , I would refer you to the O'Reilly books on Bind , they contain some good information on how this principle works

Re: DNS config

pap — Thu, 18 Apr 2002 14:54:45 GMT

What I understand from your question is that you want to quary a DNS server (another) without putting its hostname in /etc/hosts file of main DNS server.

If this is true, then you can do following.

1. Identify the domain for another DNS machine (to whom you want to query) and put its name in db.domainname file in top entries.

you will then abler to quary another DNS as well as hosts designatred to that DNS server.

suppose your domain name is
xyz.com and the another dns machine's domainnane is ab.xyz.com then enter IP address and hostname of another DNS in db.xyz file of main dns.

That will work out.
Thanks,
-pap

Re: DNS config

Shannon Petry — Thu, 18 Apr 2002 15:06:08 GMT

Look at a bind.conf entry called forwarders. This will fix the problem whether your are primary or secondary DNS.

NOTE: It is very impolite to use a forwarder without permission! Ask the person/company who maintains the server you will leach from!

Regards,
Shannon